The Chihuahuan Desert Photo by Carla DeMarco

"As we toiled across these sterile plains, where no tree offered its friendly shade, the sun glowing fiercely, and the wind hot from the parched earth – the thought would keep suggesting itself, Is this the land which we have purchased, and are to survey and keep at such a cost? As far as the eye can reach stretches one unbroken waste, barren, wild, and worthless."

So wrote John Russell Bartlett after crossing the upper reaches of the Chihuahuan Desert in Southern New Mexico in 1852, while surveying the new United States’ ADMexico boundary. Deserts are not easy to love, and our own Chihuahuan is especially intractable. It is a landscape of almost overwhelming space – flat, expansive basins abruptly interrupted by dry, bony mountains. Its sweeping expanses seem empty, forbidding, blurred by the blue haze of distance, by searing heat and dust-laden winds. But for those who come to know it, the Chihuahuan Desert is a fascinating place.

North America’s largest desert, the Chihuahuan, occupies 175,000 square miles of the United States’ Southwest and Mexico, an area two-thirds the size of the state of Texas. It stretches across Mexico and the southern Southwest like an elongated hand. The palm of the hand rests where the southern parts of the Mexican states of Durango, Chihuahua, and Coahuila meet, and the fingers stretch north across southwest Texas and southern and central New Mexico, just reaching into southeastern Arizona.

Across its tremendous area, the Chihuahuan Desert varies. But throughout it is characterized by certain shrubs – especially aromatic creosote bush, thorny mesquites and acacias, agave rosettes bearing spine-tipped leaves, and yuccas with their tall flower stalks. Unlike the Sonoran Desert to the west, the Chihuahuan is not a cactus desert, although prickly pear, cholla, and other cacti do grow here.

Deserts are defined by dryness, and the Chihuahuan is no exception. Annual precipitation over the Chihuahuan Desert’s spread ranges from 8 to nearly 12 inches. Here in southern New Mexico and west Texas, our part of the Chihuahuan averages around 9 inches of precipitation per year. But the everlasting wind and the searing sun can evaporate up to ten times that much from exposed standing water in a year.

The Chihuahuan Desert is also defined by the timing of its precipitation. It is a summer-rain-only desert; most of our yearly precipitation falls between July and September, often in intense, several-inch-per-hour, gullywashing thunderstorms. The remainder of the year is dry as often as not. Winter brings storms from the Pacific Ocean, that, wrung nearly dry by the time they reach us, bring damp air and drizzle, but very little rain. In order to survive, Chihuahuan Desert animals and plants have evolved a fascinating and diverse group of strategies to live with drought.

Barren, wild, and worthless? Perhaps to John Russell Bartlett, but not to me.

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The Mimbres River in New Mexico’s Mimbres Valley Photo by Carla DeMarco.

Autumn slips across the desert quietly. Although nights grow chill, summer’s heat lingers in the afternoons, and the greenery brought on by summer rains simply fades to dusty olive, bleached straw, and weathered brown. As the soil dries out, mesquites, desert willows, and ocotillo drop their leaves without any fanfare. But here and there where water flows – a spring, stream, an irrigation ditch, or a river – autumn shows in the rich yellows and golds of cottonwood trees.

The Rio Mimbres, “River of the Willows,” in Southern New Mexico, is an ordinary Chihuahuan Desert river, born high in the mountains, fed by winter snows and summer thunderstorms, and eventually flowing out into the open desert.

Like most Chihuahuan Desert rivers, the Mimbres disappears after it exits the mountains. Its normally-shallow flow simply sinks into the desert, leaving an empty bed to wind for miles through the landscape like a ghost river.

Thomas Antisell, mapping a route for the Southern Pacific Railroad through Southern New Mexico in 1856, described the terminus of the Mimbres as “a large collection of fresh standing water in pools or lagoons, surrounded by willow thickets.” One sunny spring day, Richard and I took a gravel road that paralleled the course of the Mimbres, headed upstream through the desert to find the river’s lagoonlike end.

At first there was no sign of either river or arroyo in the dry grasslands that we drove through. Then we spotted a shallow valley breaking the line of the grasslands to the north. But still no water.

Past a ranch, and the bright green rectangles of its irrigated hayfields, the road suddenly dropped down a small bluff right into the valley. A dense swath of native sacaton grassland, the dried flower stalks as tall as the roof of our truck, filled the valley bottom from bluff base to bluff base. Off to the left, a dotted line of willows, hackberries, box elders, ashes, and the occasional cottonwood marked the river channel.

We searched for a way through the curtain of sacaton and finally found a narrow track that headed for a grove of thick-trunked cottonwoods. Down the track, through the tall sacaton, past a small pond surrounded by old willows, along an irrigation ditch chattering with flowing water, we headed, sure that we’d found the river at last.

At the cottonwood grove, we indeed found the Rio Mimbres – and its end. A raw, recently bulldozed gravel dam several feet high plugged the river channel. Below the low dam, the channel was empty, dry. Above the dam, the river pooled, and, siphoned by an open headgate, the entire river ran into the irrigation ditch. The grove of cottonwoods, all old and misshapen, massive trunks slightly askew, circled the pond like sentinels at a gravesite.

New Mexico’s water law gives no status to rivers as such. All of the water in a river and then some can be legally diverted for “beneficial” uses, depriving fish, insects, cottonwoods, ducks, beavers, and the rest of the river community of water. With no water, the vibrant river community slowly dies. Hence the modern-day terminus of the Mimbres, no longer the lagoonlike pools, rich with life, described by Antisell in 1856-instead, the premature, but legal, death of a Chihuahuan Desert river.

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On these hot, dry June days when the horizon shimmers, set to dancing by the waves of heat that rise from the ground, I think of beaches. Not ocean beaches – playas -desert beaches. Playas are the dry, incredibly level beds of ancient lakes. Found in desert country throughout the southern Southwest and northern Mexico, and the Great Basin country of western Utah and Nevada, normally-dry playas occasionally fill with a skim of water – sometimes no more than inches deep over many square miles – after a heavy summer rain or spring snowmelt. Such lakes never last more than days or weeks, soon evaporating to leave behind huge expanses of mudflats drying in the sun. Playas were named by Spanish explorers for their resemblance to beaches – very flat beaches.

Playas are characteristic desert landforms, maintained by climates drier than they are wet, where the combination of relentless sun, wind, and thirsty air can evaporate many more times moisture from the land than falls on it in a year. Most of the Southwest’s playas formed during our last extended rainy season, many thousands of years ago. During the Pleistocene, the glacial era in the Northern Hemisphere, the climate in the Southwest was cooler and much wetter. With more precipitation, streams and rivers abounded. Yearround streams rushed down now-dry drainages in the mountains, eroding boulders, cobbles, gravel, sand, and silt as they ran, dropping the larger, heavier sediments where the water slowed down at the edge of the mountains. The basins between mountain ranges filled up with finer sands and silts, atop which floated shallow lakes.

As the climate warmed and dried some ten to twelve thousand years ago, the streams dried up and the basin-filling lakes evaporated, leaving their flat-floored beds to dry and harden to a cementlike consistency. The beds of these long-vanished lakes, including the Lordsburg playa and Lake Lucero, the playa that supplies gypsum sand for White Sands, are today’s desert playas.

When the lakes return briefly, the profusion of salty water teems with tiny aquatic lives: algae, freshwater shrimp, brine flies. These suddenly appearing residents survive the intervening months or years of drought as eggs or encysted larvae in the cracks of the dry playa, waiting for water’s next blessing.

When the water evaporates, it leaves acres of shiny, gooey mud flats, level as the surface of a pool table, encrusted with a new coat of calcium, sodium, gypsum, and other salts from the recently-departed water. The mud surface dries into curls, pie-wedge-shapes, cylinders, or shardlike plates. Polished by the ever-constant wind, it sometimes shines like glass. The flat expanses are exhilarating, Ann Zwinger says in The Mysterious Lands, “I stand, like the pivot point of a compass, in the center of the universe-a place to dance, to hoot and holler, the rearrange mountains, to count the rollicking stars at night.”

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Driving up the east side of San Augustín Pass one morning, I spotted a small, buff-colored animal with large, pointed ears lying dead on the pavement. Richard stopped the car and I walked back to see what it was. The animal was almost delicate and about the size of a house cat, with dense, buff-colored fur and a long, bushy tail tipped with black. That generous brush of a tail; the large, pointed ears; doglike face; relatively short legs; and the diminutive size gave away the identity of the dead animal: a desert kit fox.

Kit foxes are almost exclusively nocturnal, and thus rarely seen. These smallest of North American foxes are beautifully adapted to life in the desert. Their pale coloring makes them nearly invisible against a background of light-colored desert soils. Thickly-furred paws allow them to trot silently as they go about their nightly rounds; the hair also helps them float on sandy soils. Large ears help these dusk-to-dawn hunters to pick up night sounds. Even their small size may work to their advantage, making it easier to keep cool.

A kit fox’s day begins at dark, when the little fox emerges from its burrow and sets out across the desert to hunt kangaroo rats, cottontails, and other small animals. Biologists figure that a kit fox needs to eat about six ounces of meat each night in order to survive. They obtain all the water that they need from their food.

Kit foxes live alone in their underground dens for half the year. Then in winter, male and females pair up, mate, and begin preparing the natal den – used year after year – for the coming family. They haul out last year’s debris and dig new entrances. In February or March, four or five pups are born. For the first month of their life, the mother nurses the pups; the father hunts for food. Later, both parents hunt. Kit fox families stay together until autumn, when the pups are ready to live on their own.

Along with coyotes, kit foxes play an important part in controlling desert rodent and rabbit populations. For example, biologists say, the parent kit foxes must bring the pups about one hundred pounds of meat during the two months they feed them – the equivalent of about eight hundred kangaroo rats! Yet people have harassed these little foxes almost into extinction: kit foxes are trapped, shot, poisoned, and their habitat destroyed by farming or suburban growth.

I carefully picked up the limp kit fox, carried it off the highway, and laid it gently in the shade of a nearby shrub. As I walked away, I realized sadly that I’d seen only one wild kit fox since I moved here: the dead one that I had just laid down.

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In 1959, the Smithsonian Institution Annual Report carried the story of strange mirages seen near Yuma, Arizona. On hot, unusually still days, a clear image of a city appeared in the desert to the west of Yuma. It was no phantom either – the shimmering image was unmistakably that of San Diego, California, 150 miles west on the Pacific Coast, beyond several mountain ranges.

Mirages are tricks of the atmosphere, optical illusions caused when a layer of air next to the ground becomes superheated from heat stored in the soil or in dark pavement. The boundary between this hot – and therefore less dense – air and the cooler, denser air above it bends the light rays that strike it, acting like a giant mirror or lens held parallel to the ground. Depending on the altitude and extent of the layer, or layers, many kinds of mirages are produced.

Water mirages paint lakes across parched desert sands, deluding desert travelers. (The flat expanse of the Lordsburg Playa, west of Lordsburg, New Mexico, is well-known for the realism of its sparkling blue water mirages.) Like puddles stretching across dry highway pavement, these mirages are produced when the boundary between superheated and normal air reflects the sky, looking like water on the ground. More complicated mirages result when viewers can see across the abrupt hot air/cold air boundary – essentially, looking across the surface of a mirror – at the distant horizon. Mesas seem to float free, separated from the land by a layer of blue sky. Mountain ranges clone themselves, growing upside-down mirror images attached at the peaks.

More complicated – and rarer – mirages include Fata Morganas, cities appearing where none exist at all, named for the Arthurian witch Morgan le Fay. Lateral mirages reflect the image side-by-side with the actual scene, rather than above it. Several inverted pairs of images, one above the other, are called multiple mirages. One especially deceptive mirage is the Novaya Zemlya effect, named for the location in Arctic Russia where it was first seen. In the dark days of the northern winter, the sun appears to rise over the horizon weeks before it is due to return. The sun is actually below the horizon, but its image is reflected back and forth between the upper and lower boundaries of the atmospheric layer and projected above the horizon.

The clear images of the city of San Diego seen at Yuma were telescopic mirages, sharp, stable and magnified images reflected at least several hundred miles away from the source image. Telescopic mirages are rare because they require very stable air layers without the slightest whisper of wind covering many miles of landscape. Several giant lenses – abrupt hot air/cold air boundaries – transmit and magnify the image. In the case of the Yuma mirages, at least two lenses were required, to pick the image up at sea level, carry it over a 4,000 foot-high mountain mass, and reflect it again near sea level some 150 miles away.

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While jogging down the irrigation ditchbank one afternoon, I heard a loud, rattling call. A not-quite-crow-sized bird flew up from a perch above the ditch with strong, precise wingbeats, headed downstream. Its distinctive silhouette included a daggerlike bill and a ragged crest atop a big head. Its plumage was sober blue above and pure white below. A wide blue-gray stripe crossed its chest.

The clattering call, which sounds like a loud wooden rattle, and the unique silhouette gave away the bird’s identity: a belted kingfisher, named for its banded chest and its fish-catching skills. Its scientific name, Ceryle alcyon, commemorates the Greek goddess Halcyone, who threw herself into the sea in grief for her drowned husband; the gods took pity on the couple and turned them into kingfishers. (Ceryle comes from the Greek for “king of the fishes.”)

Belted kingfishers’ head and bill are proportionately larger than their small feet and short tail, making them appear top-heavy when perched. But their ungainly physique belies a graceful abilty to hover and dive. Living along shallow water from seacoasts to creeks, ponds, lakes and small rivers, belted kinfishers fish for their meals. They spot their prey – mainly small fish, but also bullfrog tadpoles, crabs, crayfish, and mussels – either from a perch or as they hover over the water. (Kingfishers also sometimes hunt over land, diving for small animals such as lizards and insects.)

Once a kingfisher spots a toothsome aquatic morsel, it dives directly into the water, seizes the fish in its powerful bill, then pushes itself to the surface with its short, strong wings, and flies back to its perch. There the kingfisher stuns the fish by whacking it on the perch, tosses the fish into the air and swallows it whole, headfirst. This latter behavior is not a display of bad manners; rather, it is an adaptation to birds’ lack of teeth. After kingfishers digest their meal, they spit out the undigestable parts – such as fins, scales, and bones – in a pellet, like hawks and owls.

Strongly territorial, kingfishers are solitary except in breeding season – April to May in the southern Southwest – when they pair up to dig a 3- to 6-foot-long horizontal nest burrow in a bank near water. The partners alternate excavating, digging with their stout bills, and pushing out dirt with their feet; depending on how clayey the soil is, burrow construction requires from three days to three weeks. Incubating the four to six eggs and raising their brood takes another two months.

Although belted kingfishers live in the southern Southwest year-round, they need permanent water. Our irrigation ditch – a seasonal stream, running only from April to October – boasts no such residents. Only in spring and fall do we hear the occasional rattling call, or see a plummeting dive as a visiting “king of fishers” passes through on its way to more promising waters.

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One searingly hot summer afternoon, I spotted a thrasher standing quite still on the ground in the shade of a small tree. The thrasher’s long curved bill was open and its wings slightly spread. At first I thought that it was sick. But then I noticed a plump white-winged dove perched on a branch overhead. It too held its mouth wide open; as I watched, I could see the skin of its throat pulsating rapidly.

Neither bird was sick. Like me, they were simply hot. Unlike people however, birds lack sweat glands and so cannot sweat to cool themselves down. But birds call on a variety of innovative techniques to beat the heat. Black vultures and wood storks, for instance, use a highly practical, if not pretty method: they defecate on their unfeathered feet and legs. As the moisture in the excretia evaporates, the bare skin cools quickly, sucking heat from the bird¹s body. Vultures and other large soaring birds also cool themselves by riding thermals to several thousand feet up in the atmosphere where the air may be 50 degrees cooler than on the ground.

Most birds use more prosaic cooling methods, such as seeking shade, bathing and/or reducing their activity – a bird in flight produces from 9 to 15 times as much heat as a resting bird. They also simply reverse their heating tactics: Instead of fluffing up their feathers, they compress their plumage to retain as little body heat as possible. And they increase circulation to unfeathered parts that will radiate heat from their blood to the outside air.

When air temperatures rise over 100 degrees, many birds – like the thrasher that I watched – pant, stepping up their breathing rate to expel hot, moist air from inside their bodies. The influx of dry outside air also cools the bird evaporatively from within by vaporizing water in its lungs and its air sacs, a system of balloon-like extensions of the lungs that fill most of the extra space in a bird¹s body, including some of its bones. Most birds can dissipate about half of their resting heat production by panting.

In addition to panting, some birds – like the perched white-winged dove – pulse the skin of their throat in and out, and at the same time, increase the blood flow to their throat skin. Like a car radiator cooling the hot water from the engine, the fluttering skin radiates the heat of the bird¹s blood to the air.

Sweat began to trickle down my back as I stood watching the two birds. After a moment, I walked on, headed for the air-conditioned campus library. As I pulled open the door, releasing a gush of cool air, I looked back. The thrasher and the white-winged dove sat motionless in the shade, their mouths open, panting.

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The ocean visited us one morning during our first winter in Las Cruces, New Mexico. My step-daughter and I walked outside to retrieve the newspaper and were enveloped in a dripping mist redolent of seaweed and saltwater.

“It smells like Puget Sound!” exclaimed Molly, drawing in great lungs full of soft, pungent air, her words exhaling silvery wisps of mist. She was right: the damp air smelled salty, with a faint tang of crabs and tide-rows of algae drying in the sun, like the sea air of our old home near the Pacific Ocean.

Except that this air blanketed the parched Chihuahuan desert, 500 miles from the nearest sea.

Water is worthy of note here: deserts are by nature dry. Our part of the Chihuahuan desert, once an arid grassland, now dominated by creosote bush, mesquites, and other shrubs, boasts an annual average precipitation of less than ten inches.

That scanty moisture comes in two very different forms, each characteristic of its season. More than half of the year’s rain comes from July through September, during our jokingly-titled “monsoon season,” often in violent arroyo-flooding thunderstorms which can dump four inches in an hour. For several weeks, perhaps longer if enough rain falls, the Rio Grande, normally shrunk to a wading stream by irrigation and groundwater withdrawals, relives the reason for its name.

Then from November to March comes winter, bringing gentle monthly tides from the faraway saltwater of the nearest ocean.

There is a distinct rhythm to these winter rains, a predictable pattern which over several days briefly transforms the sere desert air to something soft and dithering with mist. The first day, high, diaphanous cirrus clouds approach from the west, drawing a translucent shade of ice over the brilliant blue sky.

The next day, the cloud layer is thicker and lower – composed of liquid, not crystalline water – completely obscuring sun and sky. The air is perceptibly damp, and often smells foreign, like sea animals and tidal surges, evoking mornings on the ocean. That night is unusually warm, the desert insulated by the thick cloud blanket.

Before dawn the next morning the soft, whispering rain begins. It often continues through the day, varying between mist and drizzle.

Not much falls – a tenth of an inch or so – but that suffices. Once both soil and plants are moist, the smells of the distant ocean are gradually erased by those of our own fragrant desert, a distinct perfume dominated by the camphory smell of creosote bush.

The next day the front passes, taking with it the ocean: dawn brings a cloudless gold-and-turquoise sky. We are back in the pore-puckering, wrinkle-forming desert again.

For the next several weeks, perhaps a month, the dry, sunny days rule, until another visit from the ocean brings gentle, fragrant winter rain.

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My family and I moved to Las Cruces in summer, arriving on the heels of a late-evening thunderstorm. Darkness hid the landscape by the time we drove round the bend on I-25 north of town, but our noses told us where we were. The cool night air pouring in the car windows bore a rich and complicated mix of odors: citrus, sweet nectar, vinyl, camphor – emanating from creosote bush, the fragrance of our new home in the Chihuahuan desert.

Creosote bush is hard to miss in Southern New Mexico – its wiry form and sparse olive-green foliage are often all you see on alluvial fans, mesas and other sandy or gravelly soils. Creosote bush grows throughout the Southwest and northern Mexico.

Although widespread, it is not widely appreciated. Many consider the miles of creosote shrubland boring; others think it worthless, since cattle refuse to eat its resinous foliage; still others object to the fragrance produced when its coating of fifty or more volatile oils is washed off into the air by a desert rain. (In Mexico, its name is hediondilla—little stinker.) Regardless, creosote bush is an integral part of the desert, and a sophisticated example of the strategies plants use to adapt to the harsh environment.

Creosote bush’s distinctive odor and the leaves’ shiny appearance are due to a resinous, varnish-like coating which helps the plant keep from drying out. The sophisticated coating also screens the sun’s harsh rays, sheltering the delicate inner cells from heat and ultraviolet light. And it discourages grazers – the mix of waxes, volatile oils and other compounds tastes terrible and is indigestible to most animals. Only one small grasshopper, which spends its entire life on creosote, happily munches the resinous leaves.

Tasting terrible and smelling funny helps creosote bush survive in the most difficult desert environments, from parts of Baja California where four years may pass without significant rainfall, to the floor of Death Valley, where temperatures sometimes fluctuate 70 degrees from day to night. Not only does it survive, it thrives: the oldest living plant is a 9,000-year-old creosote bush in the Mojave desert of southern California.

Creosote bush’s complex chemical armor contains a veritable medicine chest: Native desert-dwellers drink teas steeped from the fragrant branches and inhale the pungent smoke to treat complaints from colds to fungal infections to rheumatism. Not surprisingly, researchers have found that the resins contain painkillers, fungicides, anti-inflammatories, and a powerful antioxidant which may be useful in treating alcoholism, liver diseases and cancer.

Whenever I breathe creosote-perfumed air after a rain, I remember this creation story told by the Pima and Papago Indians:

When Earthmaker took the first soil from his breast, they say, creosote bush was the first thing to sprout.
From the unpretentious creosote, Earthmaker created the world.

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City of Rocks. Photo by Mark Erickson.

The landscape of Southern New Mexico, West Texas, and northern Mexico has not always looked like it does today. In fact, beginning some 45 million years ago, parts of the region literally exploded, dramatically altering the shape of things. Time after time, volcanoes in the area erupted, spewing forth immense quantities of thick lava and clouds of boulder-to-dust-sized rock fragments. Torrential rains caused mudflows of volcanic debris to surge off the hillsides, drowning valleys and basins in mucky layers of debris. Lava oozed into horizontal and vertical cracks in the older layers, doming up whole areas, forming peaks, and hardening in rooster-comb-like dikes.

After several million years of relative calm, the area exploded again with volcanic activity. This time, fiery clouds of burning ash blew out of dozens of vents, burying hundreds of square miles of the landscape. The ash layers were so hot that the particles fused together when they settled, forming thick layers of solid rock called tuff. The many vents poured forth more hot ash layers, and finally, layers of basalt and other molten lava atop the earlier tuffs. At the same time, earthquakes split the landscape along a series of north-south-trending faults, pushing some sections of the earth’s crust up, and dropping others down. Some pieces broke and tilted crazily, others stayed more or less intact. Today’s many, small, north-south-trending mountain ranges, including the Franklins, the Organs and the San Andres were formed by this earth movement.

One particular layer of tuff deposited during these times of cataclysmic change now forms one of the region’s many geologic oddities: City of Rocks State Park, about 30 miles north of Deming, New Mexico. City of Rocks is named for the dense cluster of house-sized rocks that sits in a bowl-shaped basin. The rocks, eroded along natural joints into queer giant forms, are part of one of the early tuff formations from the long-vanished volcanic vents. Faulting pushed the area upwards, allowing erosion to strip away the thick layers of rock that once lay above this tuff layer. With the weight of the overlying rock layers removed, the nubbly tuff cracked into regular joints. The freeze-thawing action of water, prying action of plant roots, and the abrasive action of wind act in concert to shape a once-solid rock layer into today’s blocky sculptures.

City of Rocks is a popular recreation destination, attracting picnickers, campers, and other visitors. This fascinating area of rock sculptures has long attracted humans. When you visit City of Rocks, watch for pottery fragments, arrowheads, and grinding holes in the rocks left by earlier people. Of course, leave these artifacts untouched for others to see when visiting City of Rocks, a visible reminder of our area’s past.

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